Bigger and Better:
Welcome to the Hellmouth is based on the unscreened pilot episode shot by Buffy creator Joss Whedon. This pilot didn’t feature the Master or Angel, but does feature Jonathan - who wouldn’t officially appear in the show until season two.
All in the Past:
The first time this episode was shown in America, it was preceded by a short trailer that referred to previous slayers such as Lucy Hanover (who now regularly pops up in the Buffy books and comics). This has never been shown again in America and has never been seen overseas.
Darla the Vampire Slayer?:
Julie Benz, who plays Darla, originally auditioned for the role of Buffy whilst Sarah Michelle Gellar went up for the part of Cordelia. Imagine how different the show could have turned out it they'd got the roles!
Four songs from the band Sprung Monkey are featured in the episode: Believe, Swirl, Things are Changing and Saturated.
Back to School:
The high school exteriors were shot at Torrance High School, previously used for the series Beverly Hills 90210. When the movie She’s All That subsequently filmed there, Sarah Michelle Gellar popped up for a brief cameo during a break in her Buffy schedule.
When Buffy is looking for Willow in the Bronze, she snaps off a stool leg to use as a weapon. In the next shot, it has magically become a regular stake.